Artificial denture structures



July 23, 1957 G. E. LESTER ErAL ARTIFICIAL 'DENTURE STRUCTURES Filed lay2, 1L955 I 650.665 E LES-75E; WAL/4M LESTEQ,

INVENTORS r @2A/Ex United States Patent C ARTIFICIAL DENTURE STRUCTURESGeorge E. Lester, Encino, and William Lester, Burbank, Calif ApplicationMay 2, 1955, Serial No. 505,484 claims. (crt .s2-z) Thepresent'invention relates toiarticial denture structures, and moreparticularly to the relieving of stress in prosthetic teeth.

An object of the invention is to provide an improved prosthetic toothstructure, such asa xed bridge or a partial denture,- which givesgreater comfort to the person, restoring the function of the teeth whichit replaces, is sanitary in use, and is not harmful to the gums andother tissues in the mouth.

Another object of the invention is to provide an artir'icial toothstructure in which thev tooth is relieved of stress, the pressure on thepersons gurns being minimized considerably. The gums are relieved ofshock by permitting the artificial teeth to yield slightly under load.

A further object of the invention is to provide an artiicial toothstructure in which the tooth or teeth are allowed to yield slightlyunder load, thereby providing a stress breaker which relieves theadjacent normal or anchor teeth of some of the load and pressure. Byvirtue of the arrangement, the tendency of the anchorl or abutment teethto drift from normal position is minimized.

Yet another object of the invention is to provide a prosthetic toothstructure, in which the artificial tooth or teeth are allowed to moveindependently of one another. Y Still a further object of the inventionis to provide an improved stress breaker in denture work which can beused in full uppers and lowers.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consider-ation of severalforms in which 1t may be embodied. Such forms are shown in the draW-ings accompanying and forming part of the present specication. Theseforms will now be described in detail, for the purpose of illustratingthe general principles of the invention; but it is to be understood thatsuch detailed description is not to be taken in a limiting sense, sincethe scope of the invention is best defined by the appended claims.

Referring to the drawings:V

Figure l is a section through an artificial denture embodying theinvention;`

Fig. 2 is a section vtaken along.the'line2-2 on Fig. l;

By virtue oftheinvention, each artificial tooth is yieldably mounted soas -to have limited movement under restraint independentl'ysof anadjacent tooth, which may beanother articial'toothor an anchor tooth.The artiieial teeth maymove independently and individually of 2,799,932Patented July 23, 1957 the teeth adjacent thereto in a generallyvertical direction, to minimize any bending action that would other Wisebe imposed on the adjacent tooth or teeth. r111e restraint is providedby'one or more springs, which will only yieldV when the bite load on thearticial teeth rs .quite pronounced, the resistance to movement of theartriicral tooth increasing as the load thereon increases, 1n order toinsure proper biting action of the articial teeth against an opposedtooth or any substances therebetween. n

Despite the ability of the articial tooth to move 1ndependently of theadjacent teeth, food particles and other materials are prevented frompassing into the. art1- icial tooth structure, retaining it in a.sanitary condrtron.

As disclosed in Figs. 1 and 2, an artificial tooth 1t), which may bemade of porcelain, plastic or metal, 1s mounted in a cylindrical cavity11 provided in a denture base 12 made of a suitable material. The tooth10 can move vertically a relatively slight distance against theforce'providedby a spring 13 which may be in the form of a coilorrhelical spring member preferably conned vwithin a telescopic housingstructure secured to the artiicial tooth 10 and also to the denture base12 itself. As specifically disclosed, the telescopic housing structureincludes an outer housing 14 having a base 15 suitably secured, as bysoldering, to an outer cylindrical housing portion 16 having anoutwardly directed flange 17 at one end, this flange and the marginalportion of the base 15 being received Within an internal peripheralgroove 18 in the denture base circumscribing the cylindrical cavity 11,appropriately anchoring the outer housing 14 and its base 15 to thedenture base 12, the base 15 of the housing resting upon the bottom 19of the cylindrical cavity 11.

The outer cylindrical housing portion 16 engages the Wall of thecylindrical cavity 11, terminating in an upper web 20 merging into aninner skirt 21 extending toward the housing base 15. The inner skirt 21is spaced from the outer housing wall 16 to form a circumferentiallycontinuous groove 22 opening ina direction toward the base 15.

Similarly, an inner housing 23 is secured to the artiiicial tooth 10,its inner cylindrical wall 24 extendingupwardly into the lowerV portion'of the tooth 10, there being an upper annular ange 25 soldered, orotherwise suitably secured, to the upper end ofthe inner cylindricalwall 24 and received within a companion cavity inthe tooth, by virtue ofwhich the tooth 10 and inner cylindrical Wall 24 are rigidly anchored toeach other. EX- tending-across the inner end surface' ofthe artificialtooth and in engagement therewith is a plate 26 appropriately secured tothe inner cylindrical Wall 24, as by`being soldered thereto.

The lower portion of theiinner cylindrical wall 24 terminates in a lowerweb 27 that merges into an upwardly extending skirtrZS fitting withinthe circumferential groove 22 of the outer housing 14; The vskirt 28` ofthe inner housing and the inner cylindricalwall 24 are also spaced fromeach other to-provid a Vcircumferentially continnous groove'29" openingin' a direction toward the artilicial tooth 1o and adapted to slidablyreceive the skirt 21 of thel outer housing member. The housingstructures 14, 23 are slidable vertically with Vrespect to'veach other,being guided in such sliding movement by Virtue of the relatively closesliding lit that the respective skirts 21, 28 have in the grooves`29',22'provided in the other housing members. p

The compressed helical springV 13 is disposed within the housingstructure, one end of "the'spring bearingupon the basev 15 of thev outerhousing and the other end of the spring bearing against the plate 26"secured to the inner housing'structure and engaging the inner endsurface of the artitcialtooth 10. The-spring Y1li tends to forcetheV theinner web 27 with the -zower end of the skirt 21 of the Y. outer.housing 14 The application of the inward pressure ionV the Varticial'tooth orf suicient magnitude causes the spring 13 tov compress,Ythetooth moving within the cylindrical cavityk v11l `formedthefdefnture base to the extent Vlirnitedfby collapse of the spring toits solid height, or by engagement of the Alower web 27 with the base ofthe outer housing. During such downward movement, the skirts 21,28 areslidable along each other, as well as along the inner and outer walls ofthe housing structure, to limit the movement of the artificial tooth toa direction axially of the central common axis of thehousing'structure'and the'cylindr'icalfcavityv 11.` Duringsuch` movementof the tooth in the cavity, the

, outer surface 30 of the tooth 10 makes a relatively close sliding fitwith the wall'and the cylindrical cavity 11, to minimize the opportunity4for food and other particles to enter the cavity 11.

YWhen the pressure on the artificial tooth 10 is relieved or decreased,the spring 13 will urge the tooth outwardly of the denture base 12toward its initial position. 'I'he denture device described provides aYcompletely Venclosed housing structure for the spring 13, in view ofthe relatively close sliding iit between the inner and outer housingparts. Thus; the spring 13 and the housing structure14, 23 can beprefabricated and preassembled and need only be cast into an artificialtooth 10 and into the denture base 12 to secure a complete denturestructure in which the tooth is capable of independent movement withrespect to the denture base. Thus; the tooth does not impose any bending-or other loads on adjacent teeth, such as would be harmful to thetissues and which might cause fracture of adjoining tooth Icusps.

The housing structure and spring may be made of stainthe denture baseA12, .the exi v n tent of outward shitting being limited Vby engagementof uthe base 151i and surrounding a centering pin 35, its

other end bearing against the plate 26b and surrounding a centering pin36 of the latter. In all general respects, however, the structuredisclosed in Fig. 4 operates in the same manner as the structuredisclosed in Fig. 1, except that it is possible to provide a muchgreater spring force with the plurality of smaller springs 13b shown inFig. 4 than can be provided with the single spring 13 disclosed n Fig.l.

It is, accordingly, evident that artiiicial denture structures have beenprovided which act as stress breakers, to relieve the adjacentartificial Yor natural teeth of stress, each tooth being allowed to moveindependently of adjacent teeth, but against a predetermined resistancelafforded by the spring, or 4the like. The provision of the stressbreaker arrangement minimizes the tendency for the anchor or abutmentteeth to drift from their normal position, relieving the pressure on thepersons gums, as well a-s the shock that would be imposed thereon in theevent of a rigid'mounting of the articial teeth with respect to adjacentteeth in the persons mouth;

The'inventors claim: A l. In prosthetic tooth structures: a denture basehaving a cavity therein; anl artiicial tooth movable inV said cavity; amember in said cavity secured to said base; a mounting member in saidcavity secured to said tooth; means acting between and engaging saidmembers for yieldably urging said tooth in a direction outwardly of saidA cavity; and coengageable stop means on said members for limiting theextent of movement of said tooth lin a direction outwardly of saidcavity. 2. In prosthetic tooth structures: -a denture base having acavity therein; an artificial tooth movable in said cavity;

less steel or other. `suitable material that will have no harmfuleffects on the person and which will possess an exceedingly long life.

' In the for-m of invention disclosed in Fig. 3, the denture base 12ahas a plurality of artificial teeth 10,'10a mounted therein. Each toothmay have the same spring-like or yieldable mounting in the denture base12a, the latter, of lcourse, fitting against the gum tissue. Eachartificial tooth may move independently of the adjacent artificialtooth, to avoid a bending action on the denture base, or, if desired,the -artiiicial teeth can be secured to one another, as by use ofsuitablesoldering material 31. It isY preferred, however, that the teethV10, 10a be mounted for independent movement relative to the denturebase 33 of the spring bear against the plate 26 of the inner housing.Inasmuch as the range of movement of anarti- Aficial tooth under a loadis relatively small, the spring 13a Awill never be collapsed fully, andwill always be elective to yieldably support the artificial tooth 10a,allowing it to move inwardly of the denture base 12a under load, vandreturning it to its initial position when the load is removed. Y Y

The form of invention shown in Fig. 4 isl essentially the same as theone disclosed in Fig. ,1. However, a pluralityof helical springs 13b isprovided. Thus, the base 15b of the -outer housing may lhave -aplurality of centering pins35 therein in alignment with opposedcentering pins 36 projecting from the plate 2611. A helical compressionspring 13b is disposed in -thehonsing strucwrereah SPI-ins having 011eend Vbrarrrls'astnst a member insaid cavity secured to said base; amounting member in said cavity secured to said tooth; a spring actingbetween and engaging said members for yieldably urging said tooth in adirection outwardly of said cavity;

and coengageable Vstop means on said members for limit-` ing the extentof movement of said tooth in a direction outwardly of said cavity. 3,.In prosthetic tooth structures: a denturebase having -a cavity therein;an artificial tooth movable in said cavity; a housing member in saidcavity secured to said base; a housing member in said cavity securedtosaid tooth; a 'spring in said housing members for urging said tooth inVa direction outwardly of said cavity; and coengageable means on saidhousing members for limiting'the extent of movement of said tooth inadirection outwardly of said cavity. Y

. 4. In prosthetic tooth structures: a denture base hav` ing acavitytherein; an artificial tooth movable in said cavity; a housing member insaid cavity secured to said base; a housing member in said cavitysecured to saidv tooth; a helical compression spring in said housingmem-V bers for urging said tooth in a direction outwardly of 'saidcavity; and coengageable means on said housing members for limiting theextent of movement of said .tooth in a direction outwardly of saidcavity. i f I 5. In prosthetic tooth structures: a denture base having aplurality of cavities therein; an artificial tooth movable in each ofsaid cavities; a housing member in each of said cavities secured to saidbase; a housing member inV leach of said cavities secured to each tooth;a spring for each tooth in said housing members for urging said tooth ina direction outwardly of said cavity yindependently of movement of anadjoining tooth; and coengageable means means on said housing membersfor limiting the extent of movement of said tooth in a directionoutwardly of said cavity.

7. In prosthetic tooth structures: a denture base having a cavitytherein; an artiiicial tooth movable in said cavity; a housing member insaid cavity secured to said base; a housing member in said cavitysecured to said tooth; a plurality of helical compression springs insaid housing members for urging said tooth in a direction outwardly ofsaid cavity; and coengageable means on said housing members for limitingthe extent of movement of said tooth in a direction outwardly of saidcavity.

8. In prosthetic tooth structures: a denture base having a cavitytherein; an artiiicial tooth movable in said cavity; a rst housingmember in said cavity secured to said denture base, said memberincluding a base portion bearing against the bottom of said cavity; asecond housing member in said cavity secured to said tooth andtelescopically related to said rst housing member, said second memberhaving a plate bearing against the upper end of said tooth; a spring insaid housing members bearing against said base portion and plate forurging said tooth in a direction outwardly of said cavity; andcoengageable means on said housing members for limiting the extent ofmovement of said tooth in a direction outwardly of said cavity.

9. In prosthetic tooth structures: a denture base having a cavitytherein; an artificial tooth movable in said cavity; an outer, generallycylindrical housing member in said cavity secured to said denture base,said outer member including an outer wall portion and an inner skirtsecured to and spaced from said wall portion to provide a rstcircumferential groove opening toward the bottom of said cavity; aninner, generally cylindrical housing member in said cavity secured tosaid tooth, said inner member including an inner wall portion and anouter' skirt secured to and spaced from said inner wall portion toprovide a second circumferential groove opening toward said tooth; saidinner skirt and outer skirt being telescopically movable in said secondand rst grooves, respectively; and spring means in said housing membersfor urging said tooth in a direction outwardly of said cavity.

l0. In prosthetic tooth structures: a denture base having a cavitytherein; an artificial tooth movable in said cavity; an outer, generallycylindrical housing member in said cavity secured to said denture base7said outer member including an outer wall portion and an inner skirtsecured to and spaced from said wall portion to provide a firstcircumferential groove opening toward the bottom of said cavity; aninner, generally cylindrical housing member in said cavity secured tosaid tooth, said inner member including an inner wall portion and anouter skirt secured to and spaced from said inner wall portion toprovide a second circumferential groove opening toward said tooth; saidinner skirt and outer skirt being telescopically movable in said secondand first grooves, respectively; said outer member including a baseportion bearing against the bottom of said cavity; said inner memberincluding a plate bearing against the inner end of said tooth; andspring means in said housing member bearing against said base portionand plate for urging said tooth in a direction outwardly of said cavity.

References Cited in the tile of this patent UNITED STATES PATENTS2,577,769 Kane Dec. 11, 1951 FOREIGN PATENTS 875,990 Germany May 7, 1953

